Roman Numerals Converter Plus

The most elegant Roman numeral converter on the App Store.

Instantly convert between Arabic numbers and Roman numerals with a beautifully designed, easy-to-use interface. Whether you're decoding a movie copyright year, preparing for a Super Bowl reference, reading a clock face, or studying for class — Roman - Numeral has you covered.

CONVERT WITH EASE
• Convert numbers (1–3,999) to Roman numerals and back
• Smart custom Roman keypad that prevents invalid input
• See step-by-step breakdowns of how each numeral is built
• Tap any result to copy instantly

LEARN & EXPLORE
• Complete symbol table and subtractive rule reference
• Notable examples: current year, Super Bowl numbers, movie copyrights
• Quick quiz mode to test and sharpen your knowledge

BUILT FOR YOU
• Save conversions to history for quick reference
• Share results with one tap
• Full Dark Mode support
• Supports Dynamic Type for accessibility

Roman Numerals Converter makes conversion from Arabic numbers to Roman numerals or Roman numerals to Arabic numbers fast and easy.

Simply enter the number in the box on the top, you will get the exact representation of the number in Roman Numeral Symbols. Or enter the Roman Numeral in the box on the bottom and turn it into an ordinary number.

The numeric system represented by Roman numerals originated in ancient Rome and remained the usual way of writing numbers throughout Europe well into the Late Middle Ages. Numbers in this system are represented by combinations of letters from the Latin alphabet. Roman numerals, as used today, are based on seven symbols

I 1
V 5
X 10
L 50
C 100
D 500
M 1000

There are no letters to represent these numbers beyond several thousands

The original pattern for Roman numerals used the symbols I, V, and X (1, 5, and 10) as simple tally marks. Each marker for 1 (I) added a unit value up to 5 (V), and was then added to (V) to make the numbers from 6 to 9:

I, II, III, IIII, V, VI, VII, VIII, VIIII, X.

The numerals for 4 (IIII) and 9 (VIIII) proved problematic (among other things, they are easily confused with III and VIII), and are generally replaced with IV (one less than 5) and IX (one less than 10). This feature of Roman numerals is called subtractive notation.

The numbers from 1 to 10 (including subtractive notation for 4 and 9) are expressed in Roman numerals as follows:

I, II, III, IV, V, VI, VII, VIII, IX, X.[2]

The system being basically decimal, tens and hundreds follow the same pattern:

Thus 10 to 100 (counting in tens, with X taking the place of I, L taking the place of V and C taking the place of X):

X, XX, XXX, XL, L, LX, LXX, LXXX, XC, C.

Note that 40 (XL) and 90 (XC) follow the same subtractive pattern as 4 and 9.

Similarly, 100 to 1000 (counting in hundreds):

C, CC, CCC, CD, D, DC, DCC, DCCC, CM, M.

Again - 400 (CD) and 900 (CM) follow the standard subtractive pattern.

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